On May 19, Iran goes to the polls to select a new president. So far the campaign has been dominated by the economy. Unemployment is high, and oil prices are low. The lifting of sanctions following Tehran’s nuclear agreement with the West has yet to yield benefits. Yet the effect of sanctions — or whether the next president is a hard-liner or a relative moderate — is secondary to the largest long-term threat to Iran’s stability.

Due to gross water mismanagement and its ruinous impact on the country, Iran faces the worst water future of any industrialized nation. After the fall of the shah in 1979, water policy became a victim of bad governance and corruption, putting the country on what may be an irreversible path to environmental doom and disruption that owes nothing to sanctions or years of war with its neighbors.

Beginning in 1987, as the war with Iraq was ending, the special military force of the Iranian regime — the Islamic Revolutionary Guard Corps (IRGC) — was given a special perk. Among other strangleholds on the Iranian economy, IRGC-owned companies, including Khatam al-Anbia, its construction arm, were given control over major engineering projects throughout the country.

Recklessly, these companies began damming major rivers, changing the historical water flows of Iran. This was done to give water preferences to powerful landowners and favored ethnic communities while also transferring billions from the public treasury to IRGC leaders’ accounts. In all, since the 1979 revolution, more than 600 dam projects have been completed, contrasted with 13 dams built in Iran prior to the shah’s fall.

As the IRGC grew richer and more powerful, this same military force that today exerts influence in Syria, Yemen and elsewhere silenced farmers and environmentalists who protested river diversions by labeling them counter-revolutionaries, a crime punishable by harsh imprisonment. With its hands on the levers of power and its leaders’ pockets being filled from government accounts for these projects, no one has been able to stop these ventures.

At the same time, the government needed farmers to grow food — and pragmatically had no interest in turning them into enemies of the state. The regime turned a blind eye as growers drilled wells without controls or concerns about sustainability, giving themselves all of the groundwater they wanted. With fuel long heavily subsidized in Iran, farmers turned on their diesel pumps, and often left them on, even when fields didn’t need irrigating.

After a few years of such environmental abuse of dammed rivers and over-drafted groundwater, aquifers began to go dry and lakes shriveled. Iran’s once massive Lake Urmia, until recently 2,000-square-mile expanse, contracted 90 percent between 1985 and 2015, creating cascading regional environmental problems. Other surface water resources experienced similar shrinkage and ecological consequences.

With farmland ruined, topsoil blown away and insufficient water to grow crops, millions of farmers and herders have left the countryside to live in dismal conditions in Iran’s growing cities. Meanwhile, deserts have also expanded, and the environmental damage to the country continues.

All of this led former Iranian agriculture minister Issa Kalantari to issue a report in 2015 stating that in less than 25 years as many as 50 million Iranians — Iran’s current population is approximately 83 million — will need to be relocated. Of all the injustices and miseries that the Islamic revolution may have visited on the Iranian people — from human rights abuses to large-scale corruption to the destruction of Iran’s natural environment — turning 60 percent of the country’s citizens into internal refugees would be the cruelest of all.

Ironically, the regime seems to think that the solution for the current water crisis may be found in yet more of the same corruption-based engineering projects. More IRGC-led and government-financed water projects are afoot to redirect yet other rivers.

Farmers in Iran lead the world in inefficient use of water. Some 90 percent of Iran’s freshwater is used for agriculture. By contrast, the United States uses about 70 percent, closer to the global norm. Iran’s farmers can be as efficient as farmers elsewhere if they adopt and follow better crop rotations, incentives to save water, reuse of highly treated sewage for irrigation and use of drip irrigation to eliminate the loss of water to evaporation, among other techniques. But first, the Iranian regime, which tightly controls the nation’s political life, will need to demand that farmers give up what they have come to see as an entitlement and which the regime exploits for political gain: all of the free or cheap water a farmer could want.

Sooner or later, the music will stop. Mother Nature is forgiving only up to a point. Once aquifers are pumped dry and begin collapsing on themselves, there is no engineering project — corrupt or otherwise — that can save them. The presidential election won’t change any of that. Reining in the IRGC and reallocating the country’s water is, like much else, not in the hands of Iran’s president. The supreme leader will have to take on a system created under his less-than-supreme leadership.

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